In an internal combustion engine known from DE 198 44 202 A1 (which corresponds to U.S. Pat. No. 6,164,255), the valve train component is formed as a switchable, circular cylindrical cam follower, which is arranged so that it can move longitudinally in a receptacle configured as a bore hole and which can be moved at one longitudinal end by the cam of a camshaft against the force of the valve spring of a gas exchange valve.
The cam follower contains a hydraulic valve lash adjustment element, which requires oil as a hydraulic medium in order to fulfill its function of lash adjustment. Consequently, in the internal combustion engine a main gallery is arranged as an oil supply line to the valve lash adjustment element.
The switchable cam follower is provided with a switch element. When the camshaft rotates and the cam acts on the follower, the switch element allows the gas exchange valve to open periodically in one switch position and in the other switch position, the transfer of forces from the cam to the gas exchange valve are stopped, so that this valve remains constantly in the closed position. For the activation of the switch element, the cam follower also requires oil as hydraulic medium, which is supplied to the cam follower from a switchable oil bore in the internal combustion engine.
For dual flow oil supply to switchable valve train components according to the conventional state of the art, a first oil supply supplies the hydraulic valve lash adjustment. This oil also has a lubricating function. A second oil supply takes over the regulating function of a switch element formed as a coupling mechanism. In most cases, this dual flow supply is realized over the cylinder casing of the cam follower, which can be, e.g., a bucket tappet, a roller tappet, or a bearing element.
Disadvantages in these known valve train components are that there are additional costs due to modified engine constructions and thus associated complicated component constructions. Complicated component constructions can also be encumbered with functional disadvantages due to greater masses and throttling problems.